Not enough new stuff for owners of the previous two titles, and not enough interesting content for newcomers.
Pokemon Mystery Dungeon: Explorers of Sky is the follow up to the Darkness/Time releases earlier in the year. If you're unfamiliar with these particular types of Pokemon titles, they fall under the whole rogue-like type of RPG, as opposed to the more traditional setting of mainline Pokemon games like Diamond, Pearl, and so on. As an offshoot, the idea behind them is interesting enough, but I'm not sure I can get behind the actual execution. If you've ever played a rogue-like title before, perhaps Shiren the Wanderer, or maybe Izuna the Unemployed Ninja (both on DS), you've come to realize the sub-genre is pretty well known for some high difficulty. However, Explorers of Sky is still geared towards kids, and because of that, the difficulty is pretty low. That's not to say that a rogue-like needs to be difficult, I suppose, but the overall ease of this game, combined with no heavy death penalty, makes it an odd little hybrid that I don't see much use in playing.
Explorers of Sky contains much of the same content that the previous two games did. There are some minor changes made here, but I can't say that they're worth jumping into the game again if you've played through one of the previous two releases. If you're looking at trying out the series with this new game, however, you won't notice that it's only a slight upgrade from the originals. Obviously this is the version to play if you're going in fresh, but then again, I'm not sure that it's worth checking out in the first place.
As the game opens up, you're subjected to a number of personality questions to determine the type of Pokemon you'll start the game as. The game only stars Pokemon, there are no human trainers or gym leaders anywhere within, this is strictly about Pokemon from another dimension or world, so basically a complete side-story to whatever makes up the main Pokemon "universe". Once your type is selected, you'll be plopped down in the story as a human transported to this new world, and transformed into a Pokemon. From there you're trying to figure out who you were before, why you were brought here, and so on. At the onset of the game you're partnered up with another Pokemon (which you get to choose), and that guy or girl remains your partner throughout the rest of the game. When you enter dungeons you'll go together, and while the partner is AI controlled for the most part, you can set specials and other moves for them to use. Once all this is out of the way, you join up with a league of Explorers, which thrusts you into the main setting of the game.
Inside the league, there are a couple bulletin boards with different jobs you can take on. Outside of the main town area, there are a number of dungeons, Mystery Dungeons as the name of the game implies, unique to the world because they're constantly shifting about. Every time you enter a dungeon the layout is never the same, so you can't memorize floor or enemy patterns, it'll always be different. That's not a huge deal in the game, to be honest, most of the floors aren't too complex or difficult to traverse, and you can easily overpower most of the enemies in the game, including the few "boss" fights you'll run across. The only real challenge comes from getting overwhelmed on occasion, but that happens rarely throughout the game.
Once you've taken on a series of jobs from the bulletin boards, you enter the corresponding dungeon and try to complete whatever you have lined up. You can take on multiple jobs for one dungeon at once, but you can't switch between dungeons within a day. As soon as you're defeated or finish the jobs you have available, the day will reset and you'll start your descent all over again. Most dungeons have a preset number of floors, and they're actually pretty low, 6 or 7 levels, so it doesn't take a great deal of time to explore them top to bottom. There are some traps and enemies to beware of, but like I mentioned, you feel really overpowered for the majority of the game, which takes the challenge and thrill/danger of exploring out of the equation.
Without that challenge, I'm not sure how Explorer of Sky intends to draw in the average player. Maybe the hardcore Pokemon fans will eat this stuff up, but as a RPG fan in general; I'm left feeling a little aloof with this game. I trudged through my fair share of dungeons and jobs, but the jobs felt awfully repetitive, and the dungeon exploration didn't have much excitement to it when I realized I could literally plow through most encounters, regardless of Pokemon elemental types and other trappings that have made the Pokemon titles interesting to me before.
All together, I don't think the Explorer games are particularly well done, at least not for someone within my age demographic. If you're a hardcore fan of the franchise I'm probably not going to talk you out of picking this one up, but if you're just a fan of rogue-likes in general, or RPGs for that matter, then I'd suggest avoiding this one. It's definitely geared for a younger audience, and the gameplay gets pretty boring a few hours in. The story isn't interesting enough to keep you involved, and the gameplay doesn't elevate past mashing attacks for combat. All together, it's a disappointing title, and not one that I suggest checking out.